Taste receptor type 1 member 3 (TAS1R3), responsible for mediating taste perception, is a G protein-coupled receptor (GPCR) expressed in gustatory cells located within the taste buds on the tongue. It can form a heterodimeric receptor with TAS1R1 to elicit the umami taste response, or it can bind with TAS1R2 to form a receptor for the sweet taste response, thus a functional binding ELISA assay was conducted to detect the interaction of recombinant human TAS1R3 and recombinant mouse TAS1R1. Briefly, biotin-linked TAS1R3 were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100 ul were then transferred to TAS1R1-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST 3 times and incubation with Streptavidin-HRP for 30min, then wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50 µl stop solution to the wells and read at 450 nm immediately. The binding activity of recombinant human TAS1R3 and recombinant mouse TAS1R1 was shown in Figure 1, the EC50 for this effect is 0.31 ug/mL.